add a setBreak interface to set the break feature, now tested on FTDI chip.

usbserial/src/main/java/com/felhr/usbserial/BLED112SerialDevice.java

@@ -203,6 +203,12 @@ public class BLED112SerialDevice extends UsbSerialDevice
 
     }
 
+    @Override
+    public void setBreak(boolean state)
+    {
+        //TODO
+    }
+
     @Override
     public void setRTS(boolean state)
     {

usbserial/src/main/java/com/felhr/usbserial/CDCSerialDevice.java

@@ -245,6 +245,12 @@ public class CDCSerialDevice extends UsbSerialDevice
 
     }
 
+    @Override
+    public void setBreak(boolean state)
+    {
+        //TODO
+    }
+
     @Override
     public void setRTS(boolean state)
     {

usbserial/src/main/java/com/felhr/usbserial/CH34xSerialDevice.java

@@ -267,6 +267,12 @@ public class CH34xSerialDevice extends UsbSerialDevice
 
     }
 
+    @Override
+    public void setBreak(boolean state)
+    {
+        //TODO Auto-generated method stub
+    }
+
     @Override
     public void setParity(int parity)
     {

usbserial/src/main/java/com/felhr/usbserial/CP2102SerialDevice.java

@@ -326,6 +326,12 @@ public class CP2102SerialDevice extends UsbSerialDevice
         }
     }
 
+    @Override
+    public void setBreak(boolean state)
+    {
+        //TODO Auto-generated method stub
+    }
+
     @Override
     public void setRTS(boolean state)
     {

usbserial/src/main/java/com/felhr/usbserial/FTDISerialDevice.java

@@ -36,6 +36,13 @@ public class FTDISerialDevice extends UsbSerialDevice
     private static final int FTDI_SIO_SET_RTS_HIGH = (2 | (FTDI_SIO_SET_RTS_MASK << 8));
     private static final int FTDI_SIO_SET_RTS_LOW = (0 | (FTDI_SIO_SET_RTS_MASK << 8));
 
+    /**
+     *  BREAK on/off values obtained from linux driver
+     *  https://github.com/torvalds/linux/blob/master/drivers/usb/serial/ftdi_sio.h
+     */
+    private static final int FTDI_SIO_SET_BREAK_ON = (1<<14);
+    private static final int FTDI_SIO_SET_BREAK_OFF = (0<<14);
+
     public static final int FTDI_BAUDRATE_300 = 0x2710;
     public static final int FTDI_BAUDRATE_600 = 0x1388;
     public static final int FTDI_BAUDRATE_1200 = 0x09c4;
@@ -375,6 +382,21 @@ public class FTDISerialDevice extends UsbSerialDevice
         }
     }
 
+    /**
+     *  BREAK on/off methods obtained from linux driver
+     *  https://github.com/torvalds/linux/blob/master/drivers/usb/serial/ftdi_sio.c
+     */
+    @Override
+    public void setBreak(boolean state)
+    {
+        if(state){
+            currentSioSetData |= FTDI_SIO_SET_BREAK_ON;
+        }else{
+            currentSioSetData &= ~(FTDI_SIO_SET_BREAK_ON);
+        }
+        setControlCommand(FTDI_SIO_SET_DATA, currentSioSetData, 0);
+    }
+
     @Override
     public void setRTS(boolean state)
     {

usbserial/src/main/java/com/felhr/usbserial/PL2303SerialDevice.java

@@ -264,6 +264,12 @@ public class PL2303SerialDevice extends UsbSerialDevice
 
     }
 
+    @Override
+    public void setBreak(boolean state)
+    {
+        //TODO
+    }
+
     @Override
     public void setRTS(boolean state)
     {

usbserial/src/main/java/com/felhr/usbserial/UsbSerialDevice.java

@@ -227,6 +227,8 @@ public abstract class UsbSerialDevice implements UsbSerialInterface
     public abstract void setParity(int parity);
     @Override
     public abstract void setFlowControl(int flowControl);
+    @Override
+    public abstract void setBreak(boolean state);
 
     public SerialInputStream getInputStream() {
         if(asyncMode)

usbserial/src/main/java/com/felhr/usbserial/UsbSerialInterface.java

@@ -46,6 +46,7 @@ public interface UsbSerialInterface
     void setStopBits(int stopBits);
     void setParity(int parity);
     void setFlowControl(int flowControl);
+    void setBreak(boolean state);
 
     // Flow control commands and interface callback
     void setRTS(boolean state);

usbserial/src/main/java/com/felhr/usbserial/XdcVcpSerialDevice.java

@@ -297,6 +297,12 @@ public class XdcVcpSerialDevice extends UsbSerialDevice
         }
     }
 
+    @Override
+    public void setBreak(boolean state)
+    {
+        //TODO
+    }
+
     @Override
     public void setRTS(boolean state)
     {